Remove support for Mnemosyne rules

5 files changed, 14 insertions, 275 deletions

diff --git a/lib/syntax_tools/src/erl_prettypr.erl b/lib/syntax_tools/src/erl_prettypr.erl
index 919df337d0..81272e62de 100644
--- a/lib/syntax_tools/src/erl_prettypr.erl
+++ b/lib/syntax_tools/src/erl_prettypr.erl
@@ -50,8 +50,7 @@
               | fun((erl_syntax:syntaxTree(), _, _) -> prettypr:document()).
 -type clause_t() :: 'case_expr' | 'cond_expr' | 'fun_expr'
                   | 'if_expr' | 'receive_expr' | 'try_expr'
-                  | {'function', prettypr:document()}
-                  | {'rule', prettypr:document()}.
+                  | {'function', prettypr:document()}.
 
 -record(ctxt, {prec = 0           :: integer(),
 	       sub_indent = 2     :: non_neg_integer(),
@@ -587,8 +586,6 @@ lay_2(Node, Ctxt) ->
 		    make_case_clause(D1, D2, D3, Ctxt);
 		try_expr ->
 		    make_case_clause(D1, D2, D3, Ctxt);
-		{rule, N} ->
-		    make_rule_clause(N, D1, D2, D3, Ctxt);
 		undefined ->
 		    %% If a clause is formatted out of context, we
 		    %% use a "fun-expression" clause style.
@@ -922,15 +919,6 @@ lay_2(Node, Ctxt) ->
             D2 = lay(erl_syntax:map_field_exact_value(Node), Ctxt1),
             par([D1, floating(text(":=")), D2], Ctxt1#ctxt.break_indent);
 
-	rule ->
-	    %% Comments on the name will be repeated; cf.
-	    %% `function'.
-	    Ctxt1 = reset_prec(Ctxt),
-	    D1 = lay(erl_syntax:rule_name(Node), Ctxt1),
-	    D2 = lay_clauses(erl_syntax:rule_clauses(Node),
-			     {rule, D1}, Ctxt1),
-	    beside(D2, floating(text(".")));
-
 	size_qualifier ->
 	    Ctxt1 = set_prec(Ctxt, max_prec()),
 	    D1 = lay(erl_syntax:size_qualifier_body(Node), Ctxt1),
@@ -1069,10 +1057,6 @@ make_fun_clause_head(N, P, Ctxt) ->
 	    beside(N, D)
     end.
 
-make_rule_clause(N, P, G, B, Ctxt) ->
-    D = make_fun_clause_head(N, P, Ctxt),
-    append_rule_body(B, append_guard(G, D, Ctxt), Ctxt).
-
 make_case_clause(P, G, B, Ctxt) ->
     append_clause_body(B, append_guard(G, P, Ctxt), Ctxt).
 
@@ -1088,9 +1072,6 @@ make_if_clause(_P, G, B, Ctxt) ->
 append_clause_body(B, D, Ctxt) ->
     append_clause_body(B, D, floating(text(" ->")), Ctxt).
 
-append_rule_body(B, D, Ctxt) ->
-    append_clause_body(B, D, floating(text(" :-")), Ctxt).
-
 append_clause_body(B, D, S, Ctxt) ->
     sep([beside(D, S), nest(Ctxt#ctxt.break_indent, B)]).
 
diff --git a/lib/syntax_tools/src/erl_syntax.erl b/lib/syntax_tools/src/erl_syntax.erl
index 7ce9f231a1..3f2a3e05dd 100644
--- a/lib/syntax_tools/src/erl_syntax.erl
+++ b/lib/syntax_tools/src/erl_syntax.erl
@@ -270,10 +270,6 @@
 	 record_index_expr/2,
 	 record_index_expr_field/1,
 	 record_index_expr_type/1,
-	 rule/2,
-	 rule_arity/1,
-	 rule_clauses/1,
-	 rule_name/1,
 	 size_qualifier/2,
 	 size_qualifier_argument/1,
 	 size_qualifier_body/1,
@@ -471,19 +467,16 @@
 %%   <td>record_field</td>
 %%  </tr><tr>
 %%   <td>record_index_expr</td>
-%%   <td>rule</td>
 %%   <td>size_qualifier</td>
 %%   <td>string</td>
-%%  </tr><tr>
 %%   <td>text</td>
+%%  </tr><tr>
 %%   <td>try_expr</td>
 %%   <td>tuple</td>
 %%   <td>underscore</td>
-%%  </tr><tr>
 %%   <td>variable</td>
+%%  </tr><tr>
 %%   <td>warning_marker</td>
-%%   <td></td>
-%%   <td></td>
 %%  </tr>
 %% </table></center>
 %%
@@ -539,7 +532,6 @@
 %% @see record_expr/2
 %% @see record_field/2
 %% @see record_index_expr/2
-%% @see rule/2
 %% @see size_qualifier/2
 %% @see string/1
 %% @see text/1
@@ -608,7 +600,6 @@ type(Node) ->
 	{record_field, _, _, _, _} -> record_access;
 	{record_index, _, _, _} -> record_index_expr;
 	{remote, _, _, _} -> module_qualifier;
-	{rule, _, _, _, _} -> rule;
 	{'try', _, _, _, _, _} -> try_expr;
 	{tuple, _, _} -> tuple;
 	_ ->
@@ -691,10 +682,9 @@ is_leaf(Node) ->
 %%   <td>`comment'</td>
 %%   <td>`error_marker'</td>
 %%   <td>`eof_marker'</td>
-%%   <td>`form_list'</td>
 %%  </tr><tr>
+%%   <td>`form_list'</td>
 %%   <td>`function'</td>
-%%   <td>`rule'</td>
 %%   <td>`warning_marker'</td>
 %%   <td>`text'</td>
 %%  </tr>
@@ -707,7 +697,6 @@ is_leaf(Node) ->
 %% @see error_marker/1
 %% @see form_list/1
 %% @see function/2
-%% @see rule/2
 %% @see warning_marker/1
 
 -spec is_form(syntaxTree()) -> boolean().
@@ -720,7 +709,6 @@ is_form(Node) ->
 	eof_marker -> true;
 	error_marker -> true;
 	form_list -> true;
-	rule -> true;
 	warning_marker -> true;
 	text -> true;
 	_ -> false
@@ -3478,7 +3466,6 @@ module_qualifier_body(Node) ->
 %% @see function_clauses/1
 %% @see function_arity/1
 %% @see is_form/1
-%% @see rule/2
 
 %% Don't use the name 'function' for this record, to avoid confusion with
 %% the tuples on the form {function,Name,Arity} used by erl_parse.
@@ -4773,117 +4760,6 @@ binary_comp_body(Node) ->
 
 
 %% =====================================================================
-%% @doc Creates an abstract Mnemosyne rule. If `Clauses' is
-%% `[C1, ..., Cn]', the results represents
-%% "<code><em>Name</em> <em>C1</em>; ...; <em>Name</em>
-%% <em>Cn</em>.</code>". More exactly, if each `Ci'
-%% represents "<code>(<em>Pi1</em>, ..., <em>Pim</em>) <em>Gi</em> ->
-%% <em>Bi</em></code>", then the result represents
-%% "<code><em>Name</em>(<em>P11</em>, ..., <em>P1m</em>) <em>G1</em> :-
-%% <em>B1</em>; ...; <em>Name</em>(<em>Pn1</em>, ..., <em>Pnm</em>)
-%% <em>Gn</em> :- <em>Bn</em>.</code>". Rules are source code forms.
-%%
-%% @see rule_name/1
-%% @see rule_clauses/1
-%% @see rule_arity/1
-%% @see is_form/1
-%% @see function/2
-
--record(rule, {name :: syntaxTree(), clauses :: [syntaxTree()]}).
-
-%% type(Node) = rule
-%% data(Node) = #rule{name :: Name, clauses :: Clauses}
-%%
-%%	Name = syntaxTree()
-%%	Clauses = [syntaxTree()]
-%%
-%%	(See `function' for notes on why the arity is not stored.)
-%%
-%% `erl_parse' representation:
-%%
-%% {rule, Pos, Name, Arity, Clauses}
-%%
-%%	Name = atom()
-%%	Arity = integer()
-%%	Clauses = [Clause] \ []
-%%	Clause = {clause, ...}
-%%
-%%	where the number of patterns in each clause should be equal to
-%%	the integer `Arity'; see `clause' for documentation on
-%%	`erl_parse' clauses.
-
--spec rule(syntaxTree(), [syntaxTree()]) -> syntaxTree().
-
-rule(Name, Clauses) ->
-    tree(rule, #rule{name = Name, clauses = Clauses}).
-
-revert_rule(Node) ->
-    Name = rule_name(Node),
-    Clauses = [revert_clause(C) || C <- rule_clauses(Node)],
-    Pos = get_pos(Node),
-    case type(Name) of
-	atom ->
-	    A = rule_arity(Node),
-	    {rule, Pos, concrete(Name), A, Clauses};
-	_ ->
-	    Node
-    end.
-
-
-%% =====================================================================
-%% @doc Returns the name subtree of a `rule' node.
-%%
-%% @see rule/2
-
--spec rule_name(syntaxTree()) -> syntaxTree().
-
-rule_name(Node) ->
-    case unwrap(Node) of
-	{rule, Pos, Name, _, _} ->
-	    set_pos(atom(Name), Pos);
-	Node1 ->
-	    (data(Node1))#rule.name
-    end.
-
-%% =====================================================================
-%% @doc Returns the list of clause subtrees of a `rule' node.
-%%
-%% @see rule/2
-
--spec rule_clauses(syntaxTree()) -> [syntaxTree()].
-
-rule_clauses(Node) ->
-    case unwrap(Node) of
-	{rule, _, _, _, Clauses} ->
-	    Clauses;
-	Node1 ->
-	    (data(Node1))#rule.clauses
-    end.
-
-%% =====================================================================
-%% @doc Returns the arity of a `rule' node. The result is the
-%% number of parameter patterns in the first clause of the rule;
-%% subsequent clauses are ignored.
-%%
-%% An exception is thrown if `rule_clauses(Node)' returns
-%% an empty list, or if the first element of that list is not a syntax
-%% tree `C' of type `clause' such that
-%% `clause_patterns(C)' is a nonempty list.
-%%
-%% @see rule/2
-%% @see rule_clauses/1
-%% @see clause/3
-%% @see clause_patterns/1
-
--spec rule_arity(syntaxTree()) -> arity().
-
-rule_arity(Node) ->
-    %% Note that this never accesses the arity field of
-    %% `erl_parse' rule nodes.
-    length(clause_patterns(hd(rule_clauses(Node)))).
-
-
-%% =====================================================================
 %% @doc Creates an abstract generator. The result represents
 %% "<code><em>Pattern</em> &lt;- <em>Body</em></code>".
 %%
@@ -6368,8 +6244,6 @@ revert_root(Node) ->
 	    revert_record_expr(Node);
 	record_index_expr ->
 	    revert_record_index_expr(Node);
-	rule ->
-	    revert_rule(Node);
 	string ->
 	    revert_string(Node);
 	try_expr ->
@@ -6649,8 +6523,6 @@ subtrees(T) ->
 		record_index_expr ->
 		    [[record_index_expr_type(T)],
 		     [record_index_expr_field(T)]];
-		rule ->
-		    [[rule_name(T)], rule_clauses(T)];
 		size_qualifier ->
 		    [[size_qualifier_body(T)],
 		     [size_qualifier_argument(T)]];
@@ -6753,7 +6625,6 @@ make_tree(record_field, [[N]]) -> record_field(N);
 make_tree(record_field, [[N], [E]]) -> record_field(N, E);
 make_tree(record_index_expr, [[T], [F]]) ->
     record_index_expr(T, F);
-make_tree(rule, [[N], C]) -> rule(N, C);
 make_tree(size_qualifier, [[N], [A]]) -> size_qualifier(N, A);
 make_tree(try_expr, [B, C, H, A]) -> try_expr(B, C, H, A);
 make_tree(tuple, [E]) -> tuple(E).
diff --git a/lib/syntax_tools/src/erl_syntax_lib.erl b/lib/syntax_tools/src/erl_syntax_lib.erl
index d5f80e15f4..5b5b18d15b 100644
--- a/lib/syntax_tools/src/erl_syntax_lib.erl
+++ b/lib/syntax_tools/src/erl_syntax_lib.erl
@@ -35,8 +35,7 @@
          analyze_function_name/1, analyze_implicit_fun/1,
          analyze_import_attribute/1, analyze_module_attribute/1,
          analyze_record_attribute/1, analyze_record_expr/1,
-         analyze_record_field/1, analyze_rule/1,
-         analyze_wild_attribute/1, annotate_bindings/1,
+         analyze_record_field/1, analyze_wild_attribute/1, annotate_bindings/1,
          annotate_bindings/2, fold/3, fold_subtrees/3, foldl_listlist/3,
          function_name_expansions/1, is_fail_expr/1, limit/2, limit/3,
          map/2, map_subtrees/2, mapfold/3, mapfold_subtrees/3,
@@ -527,8 +526,6 @@ vann(Tree, Env) ->
             vann_try_expr(Tree, Env);
         function ->
             vann_function(Tree, Env);
-        rule ->
-            vann_rule(Tree, Env);
         fun_expr ->
             vann_fun_expr(Tree, Env);
         list_comp ->
@@ -569,15 +566,6 @@ vann_function(Tree, Env) ->
     Bound = [],
     {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
 
-vann_rule(Tree, Env) ->
-    Cs = erl_syntax:rule_clauses(Tree),
-    {Cs1, {_, Free}} = vann_clauses(Cs, Env),
-    N = erl_syntax:rule_name(Tree),
-    {N1, _, _} = vann(N, Env),
-    Tree1 = rewrite(Tree, erl_syntax:rule(N1, Cs1)),
-    Bound = [],
-    {ann_bindings(Tree1, Env, Bound, Free), Bound, Free}.
-
 vann_fun_expr(Tree, Env) ->
     Cs = erl_syntax:fun_expr_clauses(Tree),
     {Cs1, {_, Free}} = vann_clauses(Cs, Env),
@@ -946,7 +934,7 @@ is_fail_expr(E) ->
 %%
 %%          Forms = syntaxTree() | [syntaxTree()]
 %%          Key = attributes | errors | exports | functions | imports
-%%                | module | records | rules | warnings
+%%                | module | records | warnings
 %%
 %% @doc Analyzes a sequence of "program forms". The given
 %% `Forms' may be a single syntax tree of type
@@ -1047,16 +1035,6 @@ is_fail_expr(E) ->
 %% 	 that each record name occurs at most once in the list. The
 %% 	 order of listing is not defined.</dd>
 %%
-%%     <dt>`{rules, Rules}'</dt>
-%%       <dd><ul>
-%% 	    <li>`Rules = [{atom(), integer()}]'</li>
-%%       </ul>
-%% 	 `Rules' is a list of the names of the rules that are
-%% 	 defined in `Forms' (cf.
-%% 	 `analyze_rule/1'). We do not guarantee that each
-%% 	 name occurs at most once in the list. The order of listing is
-%% 	 not defined.</dd>
-%%
 %%     <dt>`{warnings, Warnings}'</dt>
 %%       <dd><ul>
 %% 	    <li>`Warnings = [term()]'</li>
@@ -1074,12 +1052,11 @@ is_fail_expr(E) ->
 %% @see analyze_import_attribute/1
 %% @see analyze_record_attribute/1
 %% @see analyze_function/1
-%% @see analyze_rule/1
 %% @see erl_syntax:error_marker_info/1
 %% @see erl_syntax:warning_marker_info/1
 
 -type key() :: 'attributes' | 'errors' | 'exports' | 'functions' | 'imports'
-             | 'module' | 'records' | 'rules' | 'warnings'.
+             | 'module' | 'records' | 'warnings'.
 -type info_pair() :: {key(), term()}.
 
 -spec analyze_forms(erl_syntax:forms()) -> [info_pair()].
@@ -1099,8 +1076,6 @@ collect_form(Node, Info) ->
             Info;
         {function, Name} ->
             finfo_add_function(Name, Info);
-        {rule, Name} ->
-            finfo_add_rule(Name, Info);
         {error_marker, Data} ->
             finfo_add_error(Data, Info);
         {warning_marker, Data} ->
@@ -1136,8 +1111,7 @@ collect_attribute(_, {N, V}, Info) ->
 		records        = []   :: [{atom(), [{atom(), field_default()}]}],
 		errors         = []   :: [term()],
 		warnings       = []   :: [term()],
-		functions      = []   :: [{atom(), arity()}],
-		rules          = []   :: [{atom(), arity()}]}).
+		functions      = []   :: [{atom(), arity()}]}).
 
 -type field_default() :: 'none' | erl_syntax:syntaxTree().
 
@@ -1183,9 +1157,6 @@ finfo_add_warning(R, Info) ->
 finfo_add_function(F, Info) ->
     Info#forms{functions = [F | Info#forms.functions]}.
 
-finfo_add_rule(F, Info) ->
-    Info#forms{rules = [F | Info#forms.rules]}.
-
 finfo_to_list(Info) ->
     [{Key, Value}
      || {Key, {value, Value}} <-
@@ -1197,8 +1168,7 @@ finfo_to_list(Info) ->
              {records, list_value(Info#forms.records)},
              {errors, list_value(Info#forms.errors)},
              {warnings, list_value(Info#forms.warnings)},
-             {functions, list_value(Info#forms.functions)},
-             {rules, list_value(Info#forms.rules)}
+             {functions, list_value(Info#forms.functions)}
             ]].
 
 list_value([]) ->
@@ -1229,10 +1199,6 @@ list_value(List) ->
 %%
 %% 	    <dd>where `Info = analyze_function(Node)'.</dd>
 %%
-%%   <dt>`{rule, Info}'</dt>
-%%
-%% 	    <dd>where `Info = analyze_rule(Node)'.</dd>
-%%
 %%   <dt>`{warning_marker, Info}'</dt>
 %%
 %% 	    <dd>where `Info =
@@ -1245,7 +1211,6 @@ list_value(List) ->
 %%
 %% @see analyze_attribute/1
 %% @see analyze_function/1
-%% @see analyze_rule/1
 %% @see erl_syntax:is_form/1
 %% @see erl_syntax:error_marker_info/1
 %% @see erl_syntax:warning_marker_info/1
@@ -1258,8 +1223,6 @@ analyze_form(Node) ->
             {attribute, analyze_attribute(Node)};
         function ->
             {function, analyze_function(Node)};
-        rule ->
-            {rule, analyze_rule(Node)};
         error_marker ->
             {error_marker, erl_syntax:error_marker_info(Node)};
         warning_marker ->
@@ -1829,8 +1792,6 @@ analyze_file_attribute(Node) ->
 %% The evaluation throws `syntax_error' if
 %% `Node' does not represent a well-formed function
 %% definition.
-%%
-%% @see analyze_rule/1
 
 -spec analyze_function(erl_syntax:syntaxTree()) -> {atom(), arity()}.
 
@@ -1851,37 +1812,6 @@ analyze_function(Node) ->
 
 
 %% =====================================================================
-%% @spec analyze_rule(Node::syntaxTree()) -> {atom(), integer()}
-%%
-%% @doc Returns the name and arity of a Mnemosyne rule. The result is a
-%% pair `{Name, A}' if `Node' represents a rule
-%% "`Name(<em>P_1</em>, ..., <em>P_A</em>) :- ...'".
-%%
-%% The evaluation throws `syntax_error' if
-%% `Node' does not represent a well-formed Mnemosyne
-%% rule.
-%%
-%% @see analyze_function/1
-
--spec analyze_rule(erl_syntax:syntaxTree()) -> {atom(), arity()}.
-
-analyze_rule(Node) ->
-    case erl_syntax:type(Node) of
-        rule ->
-            N = erl_syntax:rule_name(Node),
-            case erl_syntax:type(N) of
-                atom ->
-                    {erl_syntax:atom_value(N),
-                     erl_syntax:rule_arity(Node)};
-                _ ->
-                    throw(syntax_error)
-            end;
-        _ ->
-            throw(syntax_error)
-    end.
-
-
-%% =====================================================================
 %% @spec analyze_implicit_fun(Node::syntaxTree()) -> FunctionName
 %%
 %%          FunctionName = atom() | {atom(), integer()}
diff --git a/lib/syntax_tools/src/erl_tidy.erl b/lib/syntax_tools/src/erl_tidy.erl
index 38e0c2099b..db7f0939a3 100644
--- a/lib/syntax_tools/src/erl_tidy.erl
+++ b/lib/syntax_tools/src/erl_tidy.erl
@@ -792,16 +792,11 @@ keep_form(Form, Used, Opts) ->
             N = erl_syntax_lib:analyze_function(Form),
             case sets:is_element(N, Used) of
                 false ->
-                    report_removed_def("function", N, Form, Opts),
-                    false;
-                true ->
-                    true
-            end;
-        rule ->
-            N = erl_syntax_lib:analyze_rule(Form),
-            case sets:is_element(N, Used) of
-                false ->
-                    report_removed_def("rule", N, Form, Opts),
+                    {F, A} = N,
+                    File = proplists:get_value(file, Opts, ""),
+                    report({File, erl_syntax:get_pos(Form),
+                            "removing unused function `~w/~w'."},
+                           [F, A], Opts),
                     false;
                 true ->
                     true
@@ -823,12 +818,6 @@ keep_form(Form, Used, Opts) ->
             true
     end.
 
-report_removed_def(Type, {N, A}, Form, Opts) ->
-    File = proplists:get_value(file, Opts, ""),
-    report({File, erl_syntax:get_pos(Form),
-	    "removing unused ~s `~w/~w'."},
-	   [Type, N, A], Opts).
-
 collect_functions(Forms) ->
     lists:foldl(
       fun (F, {Names, Defs}) ->
@@ -837,10 +826,6 @@ collect_functions(Forms) ->
                       N = erl_syntax_lib:analyze_function(F),
                       {sets:add_element(N, Names),
                        dict:store(N, {F, []}, Defs)};
-                  rule ->
-                      N = erl_syntax_lib:analyze_rule(F),
-                      {sets:add_element(N, Names),
-                       dict:store(N, {F, []}, Defs)};
                   _ ->
                       {Names, Defs}
               end
@@ -855,11 +840,6 @@ update_forms([F | Fs], Defs, Imports, Opts) ->
             {F1, Fs1} = dict:fetch(N, Defs),
             [F1 | lists:reverse(Fs1)] ++ update_forms(Fs, Defs, Imports,
                                                       Opts);
-        rule ->
-            N = erl_syntax_lib:analyze_rule(F),
-            {F1, Fs1} = dict:fetch(N, Defs),
-            [F1 | lists:reverse(Fs1)] ++ update_forms(Fs, Defs, Imports,
-                                                      Opts);
         attribute ->
             [update_attribute(F, Imports, Opts)
              | update_forms(Fs, Defs, Imports, Opts)];
diff --git a/lib/syntax_tools/src/igor.erl b/lib/syntax_tools/src/igor.erl
index 0420508f2a..eac5af5540 100644
--- a/lib/syntax_tools/src/igor.erl
+++ b/lib/syntax_tools/src/igor.erl
@@ -1713,8 +1713,6 @@ transform(Tree, Env, St) ->
   	    transform_function(Tree, Env, St);
  	implicit_fun ->
  	    transform_implicit_fun(Tree, Env, St);
-  	rule ->
-  	    transform_rule(Tree, Env, St);
   	record_expr ->
   	    transform_record(Tree, Env, St);
   	record_index_expr ->
@@ -1778,27 +1776,6 @@ renaming_note(Name) ->
 rename_atom(Node, Atom) ->
     rewrite(Node, erl_syntax:atom(Atom)).
 
-%% Renaming Mnemosyne rules (just like function definitions)
-
-transform_rule(T, Env, St) ->
-    {T1, St1} = default_transform(T, Env, St),
-    F = erl_syntax_lib:analyze_rule(T1),
-    {V, Text} = case (Env#code.map)(F) of
-		    F ->
-			%% Not renamed
-			{none, []};
-		    {Atom, _Arity} ->
-			%% Renamed
-			Cs = erl_syntax:rule_clauses(T1),
-			N = rename_atom(
-			      erl_syntax:rule_name(T1),
-			      Atom),
-			T2 = rewrite(T1,
-				     erl_syntax:rule(N, Cs)),
-			{{value, T2}, renaming_note(Atom)}
-		end,
-    {maybe_modified(V, T1, 2, Text, Env), St1}.
-
 %% Renaming "implicit fun" expressions (done quietly).
 
 transform_implicit_fun(T, Env, St) ->